Expressive in distinct ways, these CDs by British soprano and tenor saxophonist John Butcher not only expand understanding of his distinctive solo playing, but on one session also demonstrates how he reacts in a duo situation with a free player from a parallel tradition.

That CD is At Oto, and the other musician is New York pianist Matthew Shipp. Shipp is known for his work with the most committed exponents of the tough and vociferous Free Jazz tradition as well as electro-oriented experimenters who flirt with Rock and Hip-Hop beats. Butcher, on the other hand, whose list of collaborators, is as extensive as Shipp’s, comes from the cerebral and hushed Free Music tradition, where improvisers share concepts with notated musicians, especially when it comes to utilizing electronics.

On a London gig at the Café Oto – hence the title – Shipp has a track to himself, following two solo outings by Butcher. Then the two combine for a fascinating almost half-hour duet. In contrast Bell Trove Spools is completely solo Butcher, encompassing 10 defining reed tracks by the English stylist from concerts in Houston and Brooklyn.

Neatly collecting all his soprano solos in the Brooklyn gig, Butcher’s improvisations using the smaller horn appear more concerned with technique than tale-telling. Overall then, outside of the sheer audacity of sound creation, fascination lies with itemizing how many unique textures can be sourced from Butcher’s straight horn. The answer is flutter-tonguing and reed osculation; repeated snorting glissandi mixed with reed bites; and on “The Fourth Dart”, a collection of spetrofluctuation, staccato trills and constant and repetative circular breathing that converge so that skittering note patters almost jump over one another.

The tenor saxophone tracks are in contrast invested in single techniques, with one devoted to finger-thumping key percussion and another to testing the venue’s spatial qualities with electronically amplified feedback. Surprisingly however, there’s a certain underlying lyricism expressed in Butcher’s flat-line tremolo expression along with the expected aggressive cries and continuous patterning. That makes “Perfume Screech”, the CD longest track, alive with the set’s most distinctive improvising. Moving from sections where the timbres are legato and mobile to those in which tones are mercurial and strained, Butcher sets up a call-and-response vamp with himself. Subsequently he outputs air blown through the horn’s body tube without touching the keys, or exposes slide-whistle-like chirping. The ending is all lip razzing, reed bites and tongue smacks.

Actually recorded before either part of Bell Trove Spools, Butcher tenor solo on At Oto is defining as well. Pressurized to the extent that he seems to be constantly overblowing, “Curling/Charred” is an abrasive line extended with stutters and slaps. It’s concerned with exposing the horn’s most abrasive tessitura while simultaneously bringing out the partials affiliated with each note.

For his part Shipp’s solo excursion is all about chromatic expansion, although using the pedals plus stops and strums from the strings to establish fundamentals. As power clusters judder back and forth, the pianist mixes thunderous basso notes, staccato interludes and at junctures highlights recognizable blues sequences that are infrequent visitors to any EuroImprov gig. With his high-frequency key clinking his finale is as durable as his exposition.

As a duo on “Generative Grammar”, the two improvisers appear to circle around each other rather than intersecting. The saxophonist’s inimitable tone takes on even more violent qualities so that at junctures he appears to be pulling sounds from the saxophone’s metal rather than from its reed. Meanwhile Shipp’s response to Butcher’s rugged tongue stops and slurs, is a redoubling of his muscular playing strategy. Along with hand-pumped glissandi, he uses rugged, moving strokes and octave jumps to parallel Butcher’s slurring multiphonics. Moreover, if the expression, anvil-like pounding can be used, it’s certainly present in Shipp’s playing here. Eventually a pause, following the saxophonist unleashing a series of shaking tones paralleled by lip sucking and unaccented air blowing, leads the pianist to a moderated piano sequence. Keeping his playing grounded Shipp’s carefully wrought cascades unfold at the same time as Butcher’s slurred staccato lines. This attempt at broken-chord concordance finishes the set.

Both these CDs are valuable expressions of Butcher’s ever-expanding saxophone vocabulary as well as a glimpse at Shipp’s inventive technical strategy. However the two-person expression appears to be more about playing singly at the same time rather than being true duo work. It will be interesting to chart if the Yank and Brit ever play together again.